my vertica is down which log i should check for the cause?

Hi,

I am new in Vertica . I am using community edition 3 node cluster. For couple of weeks it was working fine. Today, I am not able to connect to vertica  today, when i check the status in admintools it shows all nodes  are down. and i started the database in vertica and now it is working fine. 

which log i should check to find out the cause to stop the database?

Thanks,
Najeeb